Staged Approach Prevents Spinal Cord Injury in Hybrid Surgical-Endovascular Thoracoabdominal Aortic Aneurysm Repair: An Experimental Model

摘要

Study DesignStent GraftsPerioperative Management and AnesthesiaOperative DetailsThoracic StentingPostoperative Neurologic OutcomeHistopathologic DetailsStatistical MethodsResultsRecovery of Spinal Cord FunctionHemodynamic and Metabolic ParametersNumber of Segmental Vessels SacrificedCollateral Network Pressure in Group 1Collateral Network Pressure in Group 2 (First Stage)Collateral Network Pressure in Group 2 (Second Stage)Histopathologic FindingsIn a porcine model, we investigated the impact of sudden stent graft occlusion of thoracic intercostal arteries after open lumbar segmental artery (SA) ligation.MethodsAfter randomization into two groups, 20 juvenile Yorkshire pigs (27.1 ± 0.6 kg) underwent open lumbar SA sacrifice (T13-L5) followed by endovascular coverage of all thoracic SAs (T4-T12) at 32°C, either in a single operation (group 1) or in two stages separated by seven days (group 2). Collateral network pressure (CNP) was monitored by catheterization of the SA L1, and postoperative hind limb function was assessed using a modified Tarlov score.ResultsThe CNP in group 1 decreased to 34% of baseline, whereas CNP after lumbar SA ligation in group 2 fell to 55% of baseline (74 ± 2.4 to 25 ± 3.6 mm Hg vs 74 ± 4.5 to 41 ± 5.5 mm Hg; p < 0.0001). Subsequent thoracic stenting (group 2) led to another significant but milder drop (p = 0.002 versus stage 1) from the restored CNP (71 ± 4.2 to 54 ± 4.9 mm Hg). Five of ten pigs in group 1 suffered paraplegia, in contrast to none in group 2 (median Tarlov score 6, vs 9; p = 0.0031). Histopathologic analysis showed more severe ischemic damage to the lower thoracic (p = 0.05) and lumbar spinal cord (p = 0.002) in group 1.ConclusionsThese results underline the potential of the staged approach in hybrid procedures. Furthermore they highlight the need for established adjuncts for preventing paraplegia in hybrid and pure stent-graft protocols in which sudden occlusion of multiple SAs occurs.Abbreviations and Acronyms: CNP (collateral network pressure), KS (Kleinman score), MAP (mean arterial pressure), SA (segmental artery), SCI (spinal cord injury), TS (Tarlov score), TAAA (thoracoabdominal aortic aneurysm)CTSNet classification:26Repair of thoracoabdominal aortic aneurysms (TAAA) represents a formidable challenge. The open surgical approach, although considered the gold standard because of its solid long-term outcome, is being questioned increasingly as new, technically very appealing endovascular treatment options become available. Total endovascular repair and hybrid repair involving debranching procedures may improve outcome in selected patients, particularly in those not suitable for conventional surgery because of their general condition or significant comorbidities [